<!DOCTYPE html>
<html lang="zh-CN">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<style>
  
</style>
<body>
  
  <div id="app" >
    <div v-bind:style="bind" v-if=isbind>
      {{mes}}
    </div>
    <div>
      <p v-if="key === '晴天'">今天是晴天</p>
      <p v-else-if="key === '多云'">今天是多云</p>
      <p v-else-if="key === '雨天'">今天是雨天</p>
      <p v-else-if="key === '雾天'">今天是雾天</p>
      <p v-else>今天时阴天</p>
    </div>

    <div v-if="isbind">
      usname:
      <input type="text">
    </div>
    <div v-else>
      email:
      <input type="text">
    </div>

  </div>

  <script src="./js/vue.js"></script>
  <script type="text/javascript">
    var app = new Vue({
      el: '#app',
      data: {
        mes: "Vue",
        bind: {
          color: 'red',
          fontSize: '40px'
        },
        isbind: true,
        key: '雨天'
      },
      methods: {

      }
    })
  </script>
</body>
</html>